Abstract
Summary
The amino acid composition of the perfusate of an isolated rat liver varies markedly, and highly individually for given amino acids, over a 6-hr period. Glutamic acid, valine, isoleucine, and leucine concentrations increased whereas the concentrations of aspartic acid, proline, glycine, alanine, methionine, phenylalanine, lysine, and arginine decreased. In livers bathed in warfarin (10 μg/ml), vitamin K1 added at 2 hr in a concentration of 25 μg/ml caused a prompt and linear increase in prothrombin. The specific activity of L-leucine-1-14C added to the perfusate at zero time declined exponentially to 4% of initial values as the concentration of total leucine increased 5-fold. The prothrombin synthesized under these conditions was highly radioactive, suggesting that vitamin K stimulates de novo synthesis of this coagulation protein.
The authors wish to thank Miss Lourdes Maglasang and Miss Katherine Compagno for able technical assistance.
Get full access to this article
View all access options for this article.